Electrochemical properties and sensing applications of nanocarbons: A comparative study

Nanocarbons like graphene, carbon nanotubes, and expanded graphite feature different morphology and surface functional groups. They are thus expected to have different properties and applications. Herein, electrochemical properties of several nanocarbons including graphene nano platelets (GNPs), multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), aminated graphene (NH2-G), expanded graphite (EG) have been studied together with their composites of EG. Reversible and diffusion-controlled electrode processes for faradaic reactions of Fe(CN)(6)(3-/-4) are seen on all these electrodes. The capacitive current of MWCNTs is the biggest, while that of GO is the smallest. The composites of EG with nanocarbons feature bigger active areas than nanocarbons but smaller capacitive currents. Voltammetric response of positively and negatively charged inorganic ions (Pb-2(+), NO2-) as well as neutral organic colorants (sunset yellow and tartrazine) has been studied on these nanocarbons and their composites. The sensitive monitoring of three species has been realized on different nanocarbons or composites. Such a phenomenon is intercepted by different interactions of charged or neutral target species with nanocarbons or the composites. This study provides a systematic investigation of electro-chemistry of nanocarbons and their composites. It is thus of significance to explore different electro-chemical applications of these nanocarbons and their composites. (C) 2017 Elsevier Ltd. All rights reserved.